Beverage preparation capsules

ABSTRACT

A beverage preparation capsule ( 200 ) is provided comprising a hollow body suitable for containing a beverage preparation ingredient, the hollow body having a top end for receiving liquid into the hollow body, a bottom end for dispensing the beverage from the hollow body, and at least one side wall ( 210,212 ) between the top and bottom ends, the bottom end being in fluid communication with the top end; and a sheet of filter material ( 230 ) extending from a first position on a side wall ( 210 ) to a second position on a side wall ( 212 ), wherein said first position is relatively closer to the top end of the hollow body and the second position is relatively closer to the bottom end of the hollow body, such that the sheet of filter material ( 230 ) extends across the inside of the hollow body at an incline relative to the side wall. The beverage preparation capsule may be used with a beverage preparation apparatus in a method of preparing a beverage, particularly ground coffee or leaf tea.

The present invention relates to beverage preparation capsules.

A number of beverage-making systems are known in which a single servingof the beverage is made by inserting a capsule containing a particulatebeverage-making ingredient, such as ground coffee, into abeverage-making station of a beverage-making apparatus. The apparatusthen injects water into the capsule, where the beverage-makingingredient dissolves in, or infuses into, the water to form thebeverage. The beverage flows out of the capsule through a suitableoutlet, which may be simply an opening or perforation in the capsule orit may comprise an outlet tube that pierces an outlet region of thecapsule. The capsule may incorporate a filter to prevent passage ofsolid components such as coffee grounds out of the capsule.Beverage-making systems of this general type are described for examplein WO 94/01344, EP-A-0512468 and EP-A-0468079 (all Nestle), in U.S. Pat.No. 5,840,189 (Keurig), in EP-A-0272922 (Kenco), in EP-A-0821906 (SaraLee) and in EP-A-0179641 and WO-A-02/19875 (Mars).

GB-A-2121762, GB-A-2122881, EP-A-0179641, EP-A-0247841 and WO-A-9905044describe capsule-based beverage preparation systems of the type that arenow widely used and marketed by Mars Drinks under the registered trademark FLAVIA. An exemplary embodiment of a FLAVIA capsule according tothe state of the art is shown in FIGS. 1, 2 a and 2 b.

Referring to FIGS. 1, 2 a and 2 b, the current FLAVIA-type beveragepreparation capsule 100 comprises front and back sheets 110, 112 of aliquid- and air-impermeable sheet material permanently bonded togetheraround their top and side edges as described in more detail below. Thefront and back sheets are also bonded together along a bottom edge 120of the capsule, but this bond is releasable under the effect of heat orpressure inside the capsule. For example, the bonding of the bottom edge120 may be by means of a pressure-sensitive adhesive. Within the capsule100 is a folded web of filter material 130 bonded to the inside walls ofthe front and back sheets. The web of filter material that supports abeverage preparation ingredient 150, such as ground coffee or leaf tea.The capsule 100 further comprises a nozzle 140 having tubular bore 142.The nozzle is inserted into the top edge of the capsule and bonded in anairtight fashion to the front and back sheets, the nozzle being flangedto assist in locating the capsule 100 correctly with a beveragepreparation machine. The nozzle bore is initially sealed by a suitableairtight freshness barrier.

Referring to FIG. 2a , the sheet of web material 130 is folded to form a“W”-shape in cross-section supporting the infusible beverage preparationingredient 150. Upon introduction of liquid through the liquid conduct,the liquid pressure causes the apex 132 of the W to evert to provide adownwardly convex filter bed as shown in FIG. 2b . The eversion effectassists in the rupture of the pressure-sensitive seal of the bottom seam120 to dispense a beverage brewed in the capsule. Further details of theeverting filter webs may be found in EP-A-0179641.

Beverage-making capsules of the above type have found widespread use.However, they suffer from certain drawbacks. The manufacture of thesecapsules requires assembly of appropriately shaped components in aprecise and secure manner, which increases manufacturing costs.Moreover, the rate of flow of the beverage through the ingredient andfilter sheet may not be as fast and/or as uniform as would be desirablefor optimum beverage preparation. A difficulty that can arise with theabove systems is incomplete dissolution or extraction of the beverageingredients inside the capsule. For example, channelling of liquidthrough the compressed bed of beverage preparation ingredient duringbrewing may occur when preparing beverages using capsule-based systems,especially where relatively high pressures are required such as in thepreparation of espresso and espresso-type beverages. This channellingdirects the liquid through preferred pathways in the compressed bed ofbeverage preparation ingredient preventing uniform exposure of thebeverage preparation ingredient to the liquid. This can result in wastedbeverage preparation ingredient and a beverage having reducedconcentration of dissolved or infused material. Channelling may alsooccur if the beverage preparation ingredient is not uniformlydistributed.

Another difficulty that can arise is excessive system back-pressure dueto blocking or partial obstruction of water flow in regions where theparticulate ingredient is more dense or tightly packed, such as at thebottom regions of the filter.

The above problems can all lead to inconsistent vending performance andpoor beverage taste. Attempts have been made to solve the aboveproblems. WO-A-2005026018 describes a beverage capsule in which a filterelement has a flat base and fluted sides to improve flow of liquidthrough the filter and the beverage ingredient. However, a need stillremains for improved beverage preparation capsules, suitably but notexclusively for use in equipment of the FLAVIA type.

The present invention provides a beverage preparation capsule comprisinga hollow body suitable for containing a beverage preparation ingredient,the hollow body having a top end for receiving liquid into the hollowbody, a bottom end for dispensing the beverage from the hollow body, andat least one side wall between the top and bottom end, the bottom endbeing in fluid communication with the top end; and a sheet of filtermaterial extending from a first position on a side wall to a secondposition on a side wall, wherein said first position is relativelycloser to the top end of the hollow body and the second position isrelatively closer to the bottom end of the hollow body, such that thesheet of filter material extends across the inside of the hollow body atan incline relative to the side wall. In use, the top end receivesliquid into the hollow body for contacting with a beverage preparationingredient.

In this way, several advantages are provided, namely: easierconstruction of the capsule in manufacture; less construction materialrequired, particularly less filter material; more consistent vendingperformance; and more consistent drink taste. Specifically, by incliningthe filter material inside the hollow body of the capsule, the surfacearea of the filter and the liquid contact area of the beveragepreparation ingredient resting upon the filter is maximised, without theneed for the multiple layers or complicated folding arrangements offilter material used in the prior art. Preferably, the surface area ofthe filter material is greater than the transverse cross-sectional areaof the cavity of the hollow body. Preferably, the sheet of filtermaterial is a single sheet of non-folded material, in that the filtermaterial extending across the inside (cavity) of the hollow body is notfolded. However, it will be appreciated that the edges of the sheet offilter material may be folded to assist in securing of the filtermaterial to the capsule. By avoiding the need for multiple layers andcomplicated folding arrangements of the filter material, theconstruction complexity of the capsule is minimised. Furthermore, thegreater contact area of the beverage preparation ingredient with liquidallows for more complete brewing of the beverage preparation ingredientin a shorter time, with reduced channelling of liquid such that fewerregions of beverage preparation ingredient are left unexposed to liquidand wasted. This provides more consistent and improved vendingperformance and drink taste.

In one embodiment of the invention, the peripheral edges of the sheet offilter material are secured to the side wall or walls of the hollowbody. More preferably, the filter material is secured to the side wallor walls of the hollow body continuously around substantially the wholeperiphery of the sheet, and most preferably continuously around thewhole periphery of the sheet.

In another embodiment of the invention, the sheet of filter material isformed from one or more side walls of the hollow body. In this case, afilter region of a side wall is perforated such that the side wallbecomes at least partially porous in the filter region. The sheet offilter material will therefore comprise the same material as one or moreside walls of the hollow body, but may additionally comprise a layer ofnon-woven filter material laminated to the filter region of the sidewall.

Preferably, the sheet of filter material divides the hollow body into aninlet chamber for receiving liquid and an outlet chamber from which thebeverage is dispensed.

The hollow body may comprise a liquid inlet through which liquid canenter the hollow body. The inlet is preferably located in the top end ora top end region side wall of the hollow body. The inlet is preferably anozzle having a bore. The bore may be sealed by a frangible freshnessbarrier before use. For example, the freshness barrier may comprise anoxygen-impermeable membrane of metal foil and/or thermoplastic filmextending across the bore of the nozzle. The aforementioned featuresrelating to an inlet are particularly preferred for the sachet capsuleembodiment of the present invention, which will be discussed in greaterdetail below.

Alternatively, the top end of the hollow body may be without an inlet,but the hollow body may be cut open or pierced in use, to allow deliveryof liquid into the hollow body. This feature is particularly preferredfor the pod capsule embodiment of the present invention, which will bediscussed in greater detail below.

Preferably, the hollow body comprises an outlet through which beveragecan exit the hollow body. Preferably, the bottom end or bottom endregion side wall of the hollow body comprises an outlet channel. Theoutlet channel may be sealed in any convenient way with a seal that canbe broken during beverage preparation to allow escape of the beveragethrough the outlet channel. Conveniently, the seal is formed with aheat- and/or pressure-releasable bond, which may be broken when a fluidmedium such as air or water is introduced into the hollow body. Theaforementioned features relating to an outlet are particularly preferredfor the sachet capsule embodiment of the present invention, which willbe discussed in greater detail below.

Alternatively, the bottom end of the hollow body may be without anoutlet, but the hollow body may be cut open or pierced in use, to allowescape of beverage. This feature is particularly preferred for the podcapsule embodiment of the present invention, which will be discussed ingreater detail below.

Preferably, the beverage preparation capsule comprises a beveragepreparation ingredient supported on the sheet of filter material betweenthe filter material and the top end of the hollow body. The beveragepreparation ingredient may be an infusible beverage ingredient, forexample ground coffee or leaf tea. Preferably, the beverage preparationingredient resides in an inlet chamber of the capsule, as previouslydescribed. Preferably, the beverage preparation ingredient ishermetically sealed in the capsule body. That is to say, the hollow bodydefines an enclosure that encloses the beverage preparation ingredientin substantially air- and liquid-tight fashion until the top end of thehollow body is ruptured in use to inject water into the enclosurethrough an inlet or piercing to prepare a beverage from the ingredientinside the enclosure, and to allow the thus-prepared beverage to escapefrom an outlet or piercing created in the bottom end of the hollow bodyduring beverage preparation.

Preferably, the filter material is a web material or a nonwoven fabricmaterial. Where the beverage preparation ingredient is an infusion-typebeverage intended to be retained in the capsule after infusion (e.g.ground coffee or leaf tea), the filter material preferably has asufficiently fine mesh size to retain the infused solids while allowingfree passage of the liquid beverage. An exemplary filter material is alaminate of melt blown polypropylene sandwiched between layers ofnon-woven spun-bonded polypropylene. It can also be desirable to usecellulosic material for reasons of cost and biodegradability. Where thebeverage preparation ingredient is a dispersion- or dissolution-typebeverage and the whole contents of the capsule are intended to bedispensed, the filter material is preferably a relatively coarse meshmaterial to allow the beverage ingredient to escape. Nonetheless, thefilter material should still prevent rapid escape of a large proportionof the dispersible ingredient, to allow sufficient time for mixing withthe beverage liquid, so as to leave the pack as a liquid dispersionrather than as undispersed particles. Moreover, before use and duringstorage, the majority of the dispersible material should remain on theupper side of the coarse filter material, i.e. between the surface ofthe filter material and the top end of the hollow body.

In a preferred embodiment, the filter material has a variable porosityalong at least one dimension of its surface area, preferably thedimension which extends across the inside of the hollow body from oneside wall to another. The filter material may be less porous closer tothe top or inlet of the hollow body and more porous closer to the bottomor outlet of the hollow body. Variable porosity regions can be providedby variable thickness, variable pore size and/or variable composition ofthe filter material. Preferably, the porosity is varied by adistribution of different pore sizes or pore density.

In this way, the pressure drop (Δ-P) from the top end to the bottom endof the hollow body can be similar or the same across the whole filtermaterial, in order to encourage consistent flow of liquid through theentire beverage material, and substantially avoid liquid channellingthrough a passage of least resistance, such that substantially all ofthe beverage material is contacted with liquid.

Suitably, the capsule is a single-serve capsule that contains sufficientbeverage preparation ingredients for the preparation of a single portionof beverage, i.e. from about 25 ml to about 500 ml, preferably fromabout 100 ml to about 250 ml of beverage. For example, the capsule maycontain from about 2 g to about 25 g of ground coffee or from about 1 gto about 9 g of leaf tea, or from about 2 g to about 30 g ofwater-dispersible ingredients.

In one embodiment of the present invention, the hollow body is in theform of a sachet comprising front and back sheets of flexible filmmaterial arranged in face-to-face relationship and sealed along theiredges, wherein the inclined filter material extends from a firstposition on one sheet of the hollow body, wherein the first position isrelatively closer to the top end of the hollow body, to a secondposition on the opposite sheet, wherein the second position isrelatively closer to the bottom end of the hollow body.

The front and back sheets of the sachet embodiment may be laminatesheets, which are preferably air- and water-impermeable.

Preferably, the sheets of the sachet embodiment are permanently bondedtogether along lateral edge seams and a top seam, with an outlet regionbeing provided in a bottom seam of the sachet, and wherein a liquidinjection nozzle is inserted into the top seam or an edge seam of thesachet. In these embodiments, the construction of the sachet issubstantially the same as for a conventional FLAVIA capsule as describedabove, but with addition of the inclined filter material.

Preferably, the inclined filter material of the sachet embodimentextends from a first position on one sheet of the sachet, wherein thefirst position is relatively closer to the inlet nozzle, to a secondposition on the opposite sheet, wherein the second position isrelatively closer to the outlet region.

In one embodiment of the sachet, the sheet of filter material is adistinct piece of material from the front and back sheets of flexiblefilm material and the peripheral edges of the sheet of filter materialare secured to the front and back sheets.

In another embodiment of the sachet, the sheet of filter material isformed from either or both of the front or back sheets of flexible filmmaterial. In this case, a filter region of the flexible film material isperforated such that the material becomes at least partially porous inthe filter region. For example, a single sheet of flexible film materialmay be folded into a “N” or “

” shape, such that a first terminal portion of the sheet forms the frontof the capsule, an intermediate inclined portion of the sheet isperforated and functions as a filter material, and a second terminalportion of the sheet forms the back of the capsule. In another example,a first sheet of flexible film material may be folded into a “

” or “

” shape, such that a first portion of the first sheet forms the front ofthe capsule, and a second portion of the first sheet is perforated andfunctions as a filter material. The back of the capsule is formed from asecond sheet of flexible film material connected to the liquid permeableportion of the first sheet. In this way, a complete capsule can beprovided using only one or two sheets of flexible film material foreasier and cheaper construction. In either case, the liquid-permeableportion of the sheet may be laser perforated and may or may not becombined with a laminated layer of non-woven filter material.

The outlet region of the sachet embodiment may be sealed in anyconvenient way with a seal that can be broken during beveragepreparation to allow escape of the beverage through the outlet region.Conveniently, the seal is formed by bonding together the front and backsheets with a heat- and/or pressure-releasable bond.

In certain embodiments, the hollow body of the sachet embodiment may beformed from a single sheet in the form of a tube having an outlet regionat one end thereof. The tube may be formed by extrusion, or it may beformed from a single sheet by folding the sheet over and bonding opposededges thereof along a longitudinal lap or fin seal.

The materials used to form the hollow body of the sachet embodiment maysuitably consist essentially of flexible film materials, for example ofthe type used to form existing FLAVIA capsules. The flexible filmmaterial will usually be a laminate sheet comprising two or more of thefollowing layers: a thermoplastic sealant layer for bonding the hollowbody to other members of the capsule; a substantially gas-impermeablebarrier layer, which may be a metal film such as aluminium film or agas-barrier polymer such as polyvinyl alcohol (PvOH); adhesion layers toimprove adhesion between other layers of the laminate; structurallayers, for example to provide puncture resistance; and/or a printingsubstrate layer. The structural layers could be made of polyolefins,polyester, nylons, or other polymers as is well known in the art. In oneembodiment, the laminate material comprises a layer of polypropylene anda layer of polyvinyl alcohol (PvOH). The capsule materials may compriseat least a transparent region to provide visibility of the contents ofthe capsule.

Most preferably the sheet material of the hollow body of the sachetembodiment is a laminate comprising a layer of polypropylene and a layerof polyvinyl alcohol.

The dimensions of the sachet capsules of the sachet embodiment may besimilar to those used in the existing systems described above so thatthe capsules of the invention can be used in existing beveragepreparation equipment without modification of the equipment,particularly FLAVIA-type machines. Preferably, the sachet has a frontand back size of about 10 cm by about 7 cm, or about 10 cm by about 5cm. Preferably, the top face of the inlet nozzle of the sachet has theshape of an octahedron with two opposing sides of about 10 mm, twoopposing sides of about 3 mm, two opposing sides of about 6 mm, and twoopposing sides of about 3 mm.

In another embodiment, the hollow body is in the form of a podcomprising at least one sheet of plastic and/or metal foil materialwhich is semi-rigid, e.g. thermoformed or injection moulded. The sheetmaterial may be a laminate comprising at least one of the followinglayers: a thermoplastic sealant layer for bonding the hollow body toother members of the capsule; a substantially gas-impermeable barrierlayer, which suitably is a metal film such as aluminium film; adhesionlayers to improve adhesion between other layers of the laminate;structural layers, for example to provide puncture resistance; and/or aprinting substrate layer. The structural layers could be made ofpolyolefins, polystyrene, polyester, nylons, or other polymers as iswell known in the art. The capsule materials may comprise at least atransparent region to provide visibility of the contents of the capsule.

Preferably, the pod embodiment may comprise a first sheet that has beenformed, e.g. by thermoforming, into a cup or bowl shape with a flangedrim, and a second sheet that is bonded across the flanged rim to formthe pod. For example, the first sheet may be a relatively stiffthermoplastic sheet that has been thermoformed into a cup or bowl shapewith a flanged rim, and the second sheet is a flat sheet, which may beof flexible film material, that is bonded across the flanged rim. Inthese embodiments, the pod may have a frustoconical shape, suitably witha pierceable top and base. The bottom of the capsule is pierceable orotherwise provided with means for insertion of an outlet tube, forexample a hole with a removable cover or a hinged cover, or a septum, ora split septum, or a nozzle with a frangible freshness barrier forexample as described in WO-A-0219875.

The inclined filter material of the pod embodiment may suitably besecured to the inside surface of the pod by an adhesive or by welding toan annulus provided on the inside surface of pod, or in otherembodiments it may be held in place by retaining flanges on the insideof the pod, or it may even be retained by a liquid-permeable sheetextending over the filter material and bonded to an internal surface ofthe pod around the periphery of the filter layer. The area of the filtermaterial is suitably from about 1 cm² to about 20 cm², for example fromabout 2 cm² to about 10 cm².

The dimensions of the capsules of the pod embodiment may be similar tothose used in the existing systems described above so that the capsulesof the invention can be used in existing beverage preparation equipmentwithout modification of the equipment. Preferably, the internal volumeof the pod is from about 1 cm³ to about 100 cm³, for example from about5 cm³ to about 50 cm³.

Suitably, the side walls of the base component of the pod and the lid ofthe pod of the pod embodiment are provided with complementary engagementelements to secure the lid to the base. Suitable elements arecomplementary projections or recesses, for example threads, bayonetfittings or snap-fitting elements. Suitably, the engagement elements arereleasable to permit disassembly of the pod into the lid and the baseafter beverage preparation. Therefore, suitably the pod is not formed byadhesive or melt bonding of the lid to the base.

The bottom and side walls of the pod embodiment may be formed from air-and moisture-impermeable material as hereinbefore described so as tomaintain freshness of the beverage ingredient before use. In theseembodiments, the pod comprises an outlet that is opened before or duringbeverage preparation to release the beverage formed inside the pod. Forexample, the outlet may be an opening in the pod that is sealed by acover sheet adhered to the pod by a pressure-sensitive adhesive. Thecover sheet is removed and discarded immediately prior to assembling thecapsule. Alternatively, the sheet material of the pod may be providedwith a line of weakness, e.g. a die-cut line of weakness, defining anopening, for example a C-shaped or U-shaped line of weakness. The userpresses down on the sheet material to open the pod along the line ofweakness immediately before use. In yet other embodiments the opening issealed by a flap that is adhered around the opening by an adhesive thatis releasable by heat or pressure inside the pod arising from injectionof hot water into the pod.

In an alternative form of the pod embodiment at least a region of thebottom and/or the side walls of the pod may be made of aliquid-permeable material, which functions as the filter material forthe beverage produced by injecting water through the lid of the pod. Inthese embodiments, the bottom wall of the pod is inclined relative tothe side walls and functions as the inclined filter material previouslydescribed. The pod is suitably packaged in an air- andmoisture-impermeable package to maintain freshness of the beverageingredient before use.

In a further aspect, the present invention provides a method ofpreparing a beverage, comprising the step of passing an aqueous liquidthrough a beverage preparation capsule according to the presentinvention. The aqueous liquid is preferably water, for example at atemperature of 85° C. to 99° C. The method may be performed in thebeverage preparation apparatus already known for use with existingcapsule formats, for example as described in the patent referenceslisted above, without modification of the apparatus. The water maysuitably be injected at a pressure of 0.5 to 1.5 bar gauge forfilter-type coffee, and at higher pressures such as 5-20 bar gauge forespresso-type coffee, depending on the system.

In a method of preparing a beverage using the sachet capsule embodimentof the present invention, a water injection tube may be inserted intothe hollow body through a nozzle located in the top end or top endregion side wall of the hollow body, and then liquid may be injectingonto a beverage preparation ingredient inside the hollow body to preparethe beverage or beverage component. The bottom end or bottom end regionside wall of the hollow body may be provided with a heat- and/orpressure-sensitive seal which ruptures open upon introduction of liquidinto the hollow body, to allow beverage to escape from the hollow bodythrough the outlet tube.

In a method of preparing a beverage using the pod capsule embodiment ofthe present invention, the top end or top end region side wall of thehollow body may be pierced with an inlet tube, such that the opening ofthe inlet tube resides above the sheet of filter material, and liquidmay then be injected onto a beverage preparation ingredient inside thehollow body to prepare the beverage or beverage component. The bottomend or bottom end region side wall of the hollow body may also bepierced with an outlet tube, either before or after injecting liquidinto the hollow body, such that the opening of the outlet tube residesbelow the sheet of filter material, and then the beverage can be allowedto escape from the hollow body through the outlet tube.

The term “inclined” herein is used in the normal sense of slopingbetween a higher position to a lower position.

The term “filter material” herein is used in the sense of a materialwhich can partially or substantially prevent or retard passage of atleast a portion of beverage preparation ingredient, but allow passage ofbeverage liquid. In some embodiments, the beverage preparationingredient may be an infusible-type ingredient, such as ground coffee orleaf tea, in which case, the filter material should substantiallyprevent passage of residual waste solid ingredient, such as coffeegrounds and tea leaves, out of the capsule. However, in otherembodiments, the beverage preparation ingredient may be a dispersible-or dissolvable-type ingredient, such as soup, in which case the filtermaterial should allow passage of dispersed or dissolved ingredient withthe beverage liquid, but should prevent passage of undispersed orundissolved ingredient, out of the capsule.

The term “hollow body” is used herein in its usual sense of athree-dimensional shape including an enclosure for retaining thebeverage brewing ingredient. It will be appreciated that the hollow bodymay be of any suitable shape in plan view, including circular, square,other regular polygons, or trapezoidal. The hollow body defines aningredient chamber in which the beverage preparation ingredient may bestored, and in which the beverage may be prepared by infusion ordissolution of the beverage preparation ingredient. Preferably, theingredient chamber is suitably substantially filled by the ingredient.

The terms “top end” and “bottom end”, and related expressions such as“above”, “below”, “higher” and “lower” are relative expressions intendedto clarify the relative positions of elements of the capsule, withreference to the accompanying drawings.

While the “top end” of the capsule may indeed be the uppermost in use,it will readily be appreciated by the skilled person that this may notnecessarily be the case, depending on the orientation of the beveragepreparation machine. In any event, the “top” or “upper” regions of thecapsule are those that are upstream, and “bottom” or “lower” elementsare downstream with respect to the flow of liquid during beveragepreparation.

Similarly, the terms “front” and “back” are relative expressionsintended to clarify the relative positions of elements of the capsule,with reference to the accompanying drawings. In particular, a “front”portion of the capsule will typically be located in an opposingarrangement to a “back” portion. However, it will be readily appreciatedthat the “front” portion of the capsule need not necessarily face theuser, depending upon orientation of the capsule, in or outside of abeverage preparation machine.

The term “outlet channel” refers to a channel extending from thebeverage ingredient chamber, through which the beverage escapes from thechamber during beverage preparation. Preferably, the outlet channel issubstantially free of beverage ingredient. Preferably, the outletchannel has a length in the direction of flow of the beverage, and across-section perpendicular to that flow.

The term “frangible freshness barrier” herein is used in the sense of aseal or cap over an inlet, outlet or other opening in the capsule, suchthat the quality of a beverage preparation ingredient inside the capsuledoes not degrade over time, for example due to atmospheric moisture orbacteria. Moreover, the freshness barrier is frangible in the sense thatthe seal or cap can be broken or opened to allow the capsule to be usedto prepare a beverage.

The term “variable porosity” herein is used in the sense that theporosity of a material, such as the filter material, changes across theextent of the material. Preferably, the porosity is greater at one endof the material than at an opposite end. However, the porosity couldalso change in other directions or orientations, not limited to astrictly linear or longitudinal progression.

The term “sachet” herein is used in the sense of substantially flexiblebag or pouch, in which a beverage preparation ingredient may be stored.

The term “pod” herein is used in the sense of a substantially rigidcontainer, preferably formed from a substantially rigid bowl or cup witha substantially rigid or substantially flexible lid or top thereover, inwhich a beverage preparation ingredient may be stored.

An embodiment of the present invention will now be described further, byway of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a perspective view of a beverage preparation capsuleaccording to the prior art;

FIGS. 2a and 2b show cross-sectional views of the beverage preparationcapsule of FIG. 1 before and in use respectively;

FIG. 3 shows a perspective view of a beverage preparation capsuleaccording to the sachet embodiment of the present invention;

FIGS. 4a and 4b show a cross-sectional view of the beverage preparationcapsule of FIG. 3 before and in use respectively;

FIG. 5 shows a perspective view of a beverage preparation capsuleaccording to the pod embodiment of the present invention;

FIGS. 6a and 6b show a cross-sectional view of the beverage preparationcapsule of FIG. 5 before and in use respectively;

FIG. 7 shows an inclined filter of the present invention in use, havingvariable porosity regions.

FIG. 8 shows a filter of the present invention having variable porosityregions,

FIG. 9 shows a cross-sectional view of a beverage preparation capsuleaccording to a sachet embodiment of the present invention,

FIG. 10 shows a cross-sectional view of a beverage preparation capsuleaccording to a sachet embodiment of the present invention.

Referring to FIG. 3, the sachet embodiment of the beverage preparationcapsule of the present invention 200 comprises front and back sheets210, 212 of a liquid- and air-impermeable sheet material permanentlybonded together around their top and side edges as described in moredetail below. The front and back sheets are also bonded together along abottom edge 220 of the capsule, but this bond is releasable under theeffect of heat or pressure inside the capsule. For example, the bondingof the bottom edge 220 may be by means of a pressure-sensitive adhesive.The capsule 200 further comprises a nozzle 240 having tubular bore 242.The nozzle is inserted into the top edge of the capsule and bonded inairtight fashion to the front and back sheets, the nozzle being flangedto assist in locating the capsule 200 correctly with a beveragepreparation machine. The nozzle bore is initially sealed by a suitableairtight freshness barrier. Within the hollow cavity 260 of the capsule200 is an inclined sheet of filter material 230 bonded to the insidewalls of the front and back sheets 210, 212. The filter material 230 isa web material or a nonwoven material. The sheet of filter material 230is inclined with respect to the front and back sheets 210, 212 of thesachet, in that it extends from a higher position on the front sheet 210of the sachet that is closer to the inlet nozzle 240 to a lower positionon the back sheet 212 of the sachet that is closer to the outlet region220. The filter material 230 is bonded to the inside walls of the frontand back sheets 210, 212 around the whole periphery of the filtermaterial, thereby dividing the hollow cavity 260 of the sachet into aninlet chamber 261 for receiving liquid and an outlet chamber 262 fordispensing liquid. The sheet of filter material supports a beveragepreparation ingredient 250, such as ground coffee or leaf tea.

In use, the capsule 200 is introduced into a FLAVIA dispensing machine,which comprises a clamp to grip the nozzle 240 under the flange, and ahollow injector tube with a mechanism to insert the hollow injector tubeinto the nozzle bore 242, thereby piercing the freshness barrier. Thedispensing machine further comprises a source of hot water and a pump toinject the hot water through the injector tube into the capsule. Uponintroduction of the hot water through the injector tube and the nozzlebore 242 into the inlet chamber 261 of the capsule 200, the beveragepreparation ingredient 250 contained in the capsule 200 is mixed withthe hot water and a beverage is brewed. The bottom seam 220 of thecapsule 200 opens under the effect of heat and liquid pressure insidethe capsule, and the beverage passes through the filter sheet 230 intothe outlet chamber 262 of the capsule 200 and through the open bottom ofthe capsule 200 and is collected in a receptacle located at a receptaclestation situated directly below the capsule 200.

It can be seen that the bonding between the front and back sheets of thecapsule 200 comprises a pair of side seams 216 extending downwardly froma top seam 214 and tapering inwardly at the bottom seam 220. The sideseams 216 each include a sealed land 218 extending inwardly to form a‘waist’ to the capsule. When the capsule is in use, the additionalbonding area of the lands helps to maintain the capsule in a tubularconfiguration. In particular, the lands 218 reduce the tendency ofbottom edge of the capsule to curl upwards as it opens, therebyproviding improved control over the flow of beverage from the bottom ofthe capsule. The lands 218 thus provide a more consistent and regularopening of the capsule. Further details of this feature may be found inEP-A-0247841.

Referring to FIG. 4a , the sheet of filter material 230 is inclined withrespect to the front and back sheets 210, 212 of the sachet, extendingfrom a higher position on the front sheet 210 of the sachet that iscloser to the inlet nozzle 240 to a lower position on the back sheet 212of the sachet that is closer to the outlet region 220. The filtermaterial supports the infusible beverage preparation ingredient 250.

Referring to FIG. 4b , upon introduction of liquid through the nozzle240 into the inlet chamber 261 of the capsule 200, the liquid contactsthe beverage preparation ingredient 250 and infuses therewith to createthe beverage. The liquid beverage then passes through the sheet offilter material 230 into the outlet chamber 262, leaving behind thewaste solid beverage preparation ingredient. The passage of liquidruptures of the pressure-sensitive seal of the bottom seam 220 todispense the beverage brewed in the capsule 200. The inclined sheet ofthe filter material 230 provides a large surface area that is greaterthan the transverse cross sectional area of the hollow cavity of thesachet. In this way, the liquid and infusible beverage preparationingredient has a greater surface area through which liquid may pass,quickly and easily, without the need for excess pressure which couldrupture the sachet 200.

Referring to FIGS. 5 and 6 a, the pod embodiment of the beveragepreparation capsule of the present invention 300 comprises a cup element310 having a substantially flat base 311, a flanged top 312, andfrustoconical side walls 313 extending from the base 311 to the top 312.The cup element is formed for example by thermoforming from a suitablethermoplastic for example polystyrene. The thickness and material of thecup element are selected so that the cup element has sufficient rigidityto allow piercing of the base during beverage preparation, as describedbelow, without collapse of the cup. The flanged top 312 of the cup issealed with a flexible film lid 320 of a suitable laminate sheetmaterial as hereinbefore described. The lid 320 is bonded to the lip ofthe flanged top 312 by melt binding or adhesive bonding in aconventional fashion.

A sheet of filter material 330 is provided inside the capsule 300 in aninclined orientation. The filter material 330 is a sheet of nonwoventextile material or a web material. The filter material 330 is securedto the inside surfaces of the side walls 313 of the cup 310 by anadhesive or by welding to an annulus provided on the inside surfaces ofthe side walls of the cup. The beverage preparation ingredient 350,which in this example is ground coffee, is deposited on top of thefilter material 330 inside the capsule 300.

In use, the capsule 300 is held inside a clamp of a beverage-makingapparatus as shown in FIG. 6b . The clamp has a lower part 361 with arecess for mating engagement with the cup element 310 of the capsule,and an upper clamp part 362 that is moveable to abut the lid 320 of thecapsule. In this example, the capsule is gripped by the clamp and onlypartially enclosed by the clamp during beverage preparation. However, inalternative embodiments, the capsule may be completely enclosed by theclamp, which permits the use of elevated pressures during beveragepreparation without bursting the capsule. Alternatively, the flange 312of the capsule may simply be supported by an annular collar of thebeverage-making apparatus.

The beverage-making apparatus comprises a source of water (not shown),suitably a source of hot water, for supplying water to an injection tube371 that pierces the lid of the capsule to inject water into the capsulefor preparation of the beverage. The beverage preparation apparatusfurther comprises an outlet tube 372 that pierces the base of thecapsule and projects a short distance into the capsule, whereby the openend of the outlet tube is located below the sheet of filter material330. The inlet and outlet tubes may be fixed in spatial relationship tothe respective clamp parts, in which case piercing of the capsule takesplaces when the clamp is closed around the capsule. Alternatively, theinlet and outlet tubes may be associated with mechanisms to providereciprocating motion of the respective tubes into the capsule after thecapsule has been clamped and out of the capsule after beveragepreparation is complete. It will be appreciated that more than one inletand/or outlet tube may be provided if appropriate.

It can be seen that the capsule 300 according to this embodiment of theinvention is extremely simple and inexpensive to manufacture, and can beadapted to capsules for use in any existing beverage preparationequipment that uses beverage capsules that are pierced by an outlettube. As in the previous embodiments, the inclined sheet of the filtermaterial 330 provides a large surface area that is greater than thetransverse cross sectional area of the hollow cavity of the pod. In thisway, the liquid and infusible beverage preparation ingredient has agreater surface area through which liquid may pass, quickly and easily,without the need for excess pressure.

Referring to FIG. 7, a filter material arrangement is shown which isrepresentative of that used in the sachet embodiment of the presentinvention, in which the filter material 430 has variable porosity alongits length. However, this type of filter material may be used in anyembodiment of the invention, including any of the examples shown inFIGS. 3, 4 a, 4 b, 5, 6 a and/or 6 b. In FIG. 7, the filter material 430is thicker 431 and thus less porous closer to the top or inlet 440 ofthe sachet and thinner 432 and thus more porous closer to the bottom oroutlet 420 of the sachet. In this way, the pressure drop (Δ-P) issimilar or the same across the whole filter material 430 and aconsistent flow of liquid 470 is encouraged through the whole beveragematerial 450. This helps to avoid liquid channelling through a passageof least resistance and leaving some beverage material uncontacted withliquid.

FIG. 8 shows an alternative example of a sheet of filter material withvariable porosity along its longitudinal length, in which pores 531progressively increase in size from one lateral end 532 to anotherlateral end 533. A further alternative embodiment could use differentmaterials of the filter to provide variable porosity, for examplematerials with variable hydrophobicity.

FIG. 9 shows an embodiment of a sachet 600 in which the front sheet 610,filter material 630 and back sheet 612 are formed from a single sheet ofa liquid- and air-impermeable material folded into an “

” shape (alternatively the sheet could be folded into a “N” shape,simply being the mirror image of the sachet of FIG. 9). Since the sheetmaterial is liquid- and air-impermeable material, a filter region 630 ofthe sheet is perforated such that the sheet becomes at least partiallyporous in the filter region 630. The sheet may be laser perforated andmay be combined with an additional laminated layer of non-woven filtermaterial. The front and back sheets 610, 612 are permanently bondedtogether around their top and side edges, with the filter portion of thesheet 630 being left free to extend across the interior of the sachet,thereby dividing the hollow cavity of the sachet into an inlet chamber661 for receiving liquid and an outlet chamber 662 for dispensingliquid. The front and back sheets 610, 612 are also bonded togetheralong a bottom edge 620 of the capsule, but this bond is releasableunder the effect of heat or pressure inside the capsule. For example,the bonding of the bottom edge 620 may be by means of apressure-sensitive adhesive. The capsule 600 further comprises a nozzle640 having tubular bore. The nozzle is inserted into the top edge of thecapsule and bonded in airtight fashion, the nozzle being flanged toassist in locating the capsule 600 correctly with a beverage preparationmachine. The nozzle bore is initially sealed by a suitable airtightfreshness barrier. The sheet of filter material 630 supports a beveragepreparation ingredient 650, such as ground coffee or leaf tea.Preferably, the perforations may be more numerous in the lower regionsof the filter material 630, such that the porosity of the filtermaterial 630 is greater closer to the outlet 620 of the sachet and lessporous closer to the inlet nozzle 640.

FIG. 10 shows another embodiment of a sachet 700 in which the frontsheet 710 and filter material 730 are formed from a first sheet of aliquid- and air-impermeable material, folded into a “V” shape(alternatively the sheet could be folded into a “Λ” shape). Since thesheet material is liquid- and air-impermeable, a filter region 730 ofthe sheet is perforated such that the sheet becomes at least partiallyporous in the filter region 730. The sheet may be laser perforated andmay be combined with a laminated layer of non-woven filter material. Asecond sheet of liquid- and air-impermeable material is connected to thefilter material portion 730 of the first sheet to form the back sheet712 of the sachet. The front and back sheets 710, 712 are permanentlybonded together around their top and side edges, with the filter portionof the sheet 730 being left free to extend across the interior of thesachet, thereby dividing the hollow cavity of the sachet into an inletchamber 761 for receiving liquid and an outlet chamber 762 fordispensing liquid. The front and back sheets 710, 712 are also bondedtogether along a bottom edge 720 of the capsule, but this bond isreleasable under the effect of heat or pressure inside the capsule. Forexample, the bonding of the bottom edge 720 may be by means of apressure-sensitive adhesive. The capsule 700 further comprises a nozzle740 having tubular bore. The nozzle is inserted into the top edge of thecapsule and bonded in airtight fashion, the nozzle being flanged toassist in locating the capsule 700 correctly with a beverage preparationmachine. The nozzle bore is initially sealed by a suitable airtightfreshness barrier. The sheet of filter material 730 supports a beveragepreparation ingredient 750, such as ground coffee or leaf tea.Preferably, the perforations in the filter material 730 may be morenumerous in the lower regions of the filter material 730, such that theporosity of the filter material 730 is greater closer to the outlet 720of the sachet and less porous closer to the inlet nozzle 740.

It should be understood that the above embodiments have been describedby way of example only. Many other embodiments falling within the scopeof the accompanying claims will be apparent to the skilled reader. Itwill further be understood that any feature disclosed in relation to anyone embodiment may alternatively or additionally be present in any ofthe other embodiments.

1. A beverage preparation capsule comprising a hollow body suitable for containing a beverage preparation ingredient, the hollow body having a top end for receiving liquid into the hollow body, a bottom end for dispensing the beverage from the hollow body, and at least one side wall between the top and bottom ends, the bottom end being in fluid communication with the top end; and a sheet of filter material extending from a first position on a side wall to a second position on a side wall, wherein said first position is relatively closer to the top end of the hollow body and the second position is relatively closer to the bottom end of the hollow body, such that the sheet of filter material extends across the inside of the hollow body at an incline relative to the side wall.
 2. The beverage preparation capsule of claim 1, wherein the sheet of filter material is secured to the side wall or walls of the hollow body around the periphery of the sheet.
 3. The beverage preparation capsule of claim 1, wherein a region of a side wall is at least partially porous, such that the porous region of the side wall acts as the sheet of filter material.
 4. The beverage preparation capsule of claim 1, wherein the sheet of filter material divides the hollow body into an inlet chamber for receiving liquid and an outlet chamber from which the beverage is dispensed.
 5. The beverage preparation capsule of claim 1, wherein the surface area of the filter material is greater than the transverse cross-sectional area of the cavity of the hollow body.
 6. The beverage preparation capsule of claim 1, wherein the sheet of filter material is a single sheet of non-folded material.
 7. (canceled)
 8. (canceled)
 9. (canceled)
 10. The beverage preparation capsule of claim 1, comprising a beverage preparation ingredient supported on the sheet of filter material between the filter material and the top end of the hollow body, the beverage preparation ingredient preferably being ground coffee or leaf tea.
 11. (canceled)
 12. (canceled)
 13. The beverage preparation capsule of claim 1, wherein the sheet of filter material has a variable porosity along at least one dimension of its surface area.
 14. The beverage preparation capsule of claim 13, in which the variable porosity is provided by variable thickness, variable pore size, or variable composition of the filter material.
 15. The beverage preparation capsule of claim 13, wherein the filter material is less porous closer to the top or inlet of the hollow body and more porous closer to the bottom or outlet of the hollow body.
 16. (canceled)
 17. The beverage preparation capsule of claim 1, wherein the hollow body is in the form of a sachet comprising front and back sheets of flexible film material arranged in face-to-face relationship and sealed along their edges, wherein the inclined sheet of filter material extends from a first position on one sheet of the hollow body, wherein said first position is relatively closer to top end of the hollow body, to a second position on the opposite sheet of the hollow body, wherein said second position is relatively closer to the bottom end of the hollow body.
 18. (canceled)
 19. (canceled)
 20. The beverage preparation capsule of claim 17, wherein the inclined sheet of filter material extends from a first position on one sheet of the hollow body, wherein said first position is relatively closer to the inlet nozzle, to a second position on the opposite sheet of the hollow body, wherein said second position is relatively closer to the outlet region.
 21. (canceled)
 22. The beverage preparation capsule of claim 17, wherein a region of the flexible film material of the front and/or back sheet is at least partially porous, such that the porous region of the flexible film material acts as the sheet of filter material.
 23. The beverage preparation capsule of claim 17, wherein the flexible film material of the hollow body is a laminate comprising two or more of the following layers: a thermoplastic sealant layer for bonding the hollow body to other members of the capsule; a substantially gas-impermeable barrier layer; adhesion layers to promote adhesion between the layers of the laminate; structural layers.
 24. The beverage preparation capsule of claim 23, wherein the sheet material of the hollow body is a laminate comprising a layer of polypropylene and a layer of polyvinyl alcohol. 25.-28. (canceled)
 29. A method of preparing a beverage, comprising the step of passing an aqueous liquid through a beverage preparation capsule according to claim
 1. 30. The method of claim 29, comprising the step of inserting a water injection tube into the hollow body through a nozzle located in the top end or top end region side wall of the hollow body, and then injecting liquid onto a beverage preparation ingredient inside the hollow body to prepare the beverage or beverage component, wherein the bottom end or bottom end region side wall of the hollow body is provided with a heat- and/or pressure-sensitive seal which ruptures open upon introduction of liquid into the hollow body, to allow beverage to escape from the hollow body through the outlet tube.
 31. (canceled) 32.-35. (canceled) 